A bedding assembly having a storage area integrated therewith. In the light scanning device, a phase modulation portion is provided to at least a portion of the phase-type optical element, and a phase difference between the phase modulation portion and a region other than the phase modulation portion is not \u03c0 radian. The characteristics of the structural elements are discriminated from the image in the vicinity of the structural element candidates, at a higher accuracy than when the structural elements were detected. Two of the holes diagonally positioned on the outline are located in one of corners and at an inward position of the wiring board, while the remaining two are located at intermediate parts of two sides embracing the corner.